Landslides

Capable of occurring anywhere in the United States, landslides result in upwards of one billion dollars of damage annually. Some landslides can occur slowly over the course of a few weeks or years while others can move rapidly and destroy property and lives within a matter of minutes. Landslides can be triggered by a number of events such as periods of intense rainfall or rapid snowmelt, seismic or volcanic activity, and wildfires. Landslides can also be triggered by human activities such as large-scale irrigation. Regardless of the triggers that cause landslides, a basic understanding of this natural phenomenon is crucial when preparing for its occurrence.

The term landslide is used to describe the downslope movement of soil, rock, and other organic materials under the influence of gravity. This term includes a wide range of ground movements that can be categorized into five general types. These include slides, spreads, flows, falls, and topples. Each type of landslide is discussed in more detail in the table below.

Type

Description

Example

Slides

The downslope movement of material along a surface rupture. This type of landslide includes both transitional and rotational landslides.

Spreads

The extension of a cohesive mass of soil or rock over an underlying liquefied layer.

Flows

A viscous mixture of water, soil, rock, and other organic materials that has become a slurry. This viscous mixture often moves rapidly down slopes. There are multiple types of flows, including, debris flows, avalanches, earthflows, mudflows, and creeps.

Falls

The abrupt movement of a large mass, such as a boulder or a rock, that has detached from a steep slope or cliff and free-falls or rolls downslope.

Topples

The abrupt forward movement of a large mass about a pivot point resulting in the end-over-end motion of the mass as it moves downslope.

To learn more about specific types of landslides and the mechanisms that cause them, review The Landslide Handbook.

Before a Landslide

Taking a few steps prior to severe weather will help to ensure that both you and your family are adequately prepared for a landslide. One of the first actions you should take when preparing for a landslide is to contact local experts to learn about the prevalence of landslides in your community. Areas where landslides have occurred in the past are more likely to experience them in the future. As a result, it is recommended that citizens living in high-risk areas take preventative measures such as installing flexible pipe fittings or planting ground foliage. Taking preventative actions prior to a disaster will help to minimize property damage incurred by future landslides.

Additionally, you can obtain a ground assessment of your property. This detailed analysis of your property will help to determine landslide potential and inform you of any specific corrective measures that need to be taken. If you are building a home or other residence it is recommended that you follow proper land-use principles and avoid building near steep slopes, close to mountain edges, or near natural drainages.

It is also important to review the warning signs of landslides with all family members. Being able to recall and recognize these signs will enable you and your family to identify imminent landslide hazards. Warning signs of a landslide can include newly saturated areas of ground, tilted or bent trees, sunken or cracked roadbeds, and unusually droopy or taught utility lines. Visit the USGS Landslides Hazard Program website for a complete list of landslide warning signs.

As with any other disaster, it is important that you have a family emergency communication plan as well as a disaster supplies kit. When composing your plan, make sure to identify multiple escape routes and discuss what to do during a landslide with all family members. Additionally, having a well-maintained disaster supplies kit will help to ensure that you and your family are able to survive in the event that a landslide blocks access to your property and emergency responders are initially unable to reach you.

In addition to taking all of the actions discussed above, it is suggested that you contact your insurance agent and discuss insurance options. Generally, landslide insurance is not offered in the United States. However, some damage resulting from debris flows may be covered by flood insurance policies from the National Flood Insurance Program (NFIP). Visit FloodSmart.gov to learn more about the National Flood Insurance Act and what it may cover in your area.

During a Landslide

Landslides can occur suddenly and without warning. As a result, it is crucial that you stay awake if you suspect that a landslide is imminent. Additionally, it is important that you stay alert and listen for any unusual sounds such as trees cracking, boulders knocking together, or a low, distant rumble. If you hear any of these sounds or are advised to evacuate by local officials follow your evacuation plan and move quickly. In the event that you are unable to leave your home and a landslide occurs, curl up into a ball and protect your head. Visit Ready.gov for more information on what to do during a landslide.

After a Landslide

Immediately after a landslide, it is of the utmost importance that you stay away from the slide area as additional slides and flooding may occur. Without putting yourself at risk, look for damaged roadways, utility lines, and water pipes and report them to the appropriate authorities. Reporting these hazards will ensure that they are shut off as quickly as possible, preventing injury to victims and emergency responders. If possible, check for injured or trapped individuals without entering the slide area and report their location to emergency personnel.

If you have been evacuated or feel it is unsafe to re-enter your home or neighborhood, seek safety at the nearest public shelter. Continue to listen to local media to ensure that you receive the most up to date and accurate emergency information.

Once authorities have determined that it is safe to re-enter the slide area, check the foundation of your home and surrounding landscape for damage. Damage to any of these areas may indicate further interior damage and should signal to you that it is unsafe to re-enter your home. You should seek the advice of a professional to determine the structural stability of your home. Additionally, you should replant damaged ground cover as soon as possible since the loss of this vegetation can lead to flash flooding and additional landslides. You can also consider consulting a geotechnical expert to learn more about mitigation methods that you can utilize around your home and property to reduce landslide risk.

Landslides in Klamath County

Landslides are some of the most common and destructive natural hazards in Oregon. Annually, landslides cause millions of dollars of damage across the state. A number of factors, including climate, geology, and topography, make areas in and west of the Cascade Mountain Range particularly susceptible to this natural phenomenon. Additionally, expanding population growth has driven residential development onto steep slopes and other landslide-prone areas. As a result, an increasing emphasis has been placed on landslide research and mapping efforts.

One such effort is the Statewide Landslide Information Database for Oregon (SLIDO). This project serves as a database of mapped landslides across the state and was created to identify landslide hazards. The information in this database includes both historical and mapped landslide data as well as an interactive map that allows you to view landslide hazards in your area.

Although not a major hazard in Klamath County, landslides still pose a threat to citizens living in landslide-prone areas. Evidence of 582 landslides has been found throughout the county with a majority of mapped landslide activity occurring northeast of Klamath Falls. Most notably, the Klamath Falls Earthquakes of 1993 caused a landslide along U.S. Highway 97 that resulted in the death of a motorist.